1. Field of the Invention
The present invention relates to an electronic component testing socket used for loading an electronic component to be tested in an electronic component testing apparatus for testing performance and functions of an electronic component, such as in IC device and an electronic component testing socket base used for mounting the electronic component testing socket. Also, the present invention relates to an electronic component testing unit wherein the electronic component testing socket is mounted on the electronic component testing socket base and an electronic component testing apparatus wherein the electronic component testing socket or an electronic component testing unit is mounted.
2. Description of the Related Art
In a production process of an electronic component, such as an IC device, an electronic component testing apparatus for testing performance and functions of a finally produced IC chip and a strip format IC device, etc. at its transition stage is necessary. As an example of such an electronic component testing apparatus, there is known an IC device testing apparatus for testing performance and functions of an IC device under a variety of thermal conditions, such as an ordinary temperature, low temperature and high temperature.
A test of an IC device using the IC device testing apparatus is for example conducted as described below. After transferring an IC device to be tested to above a test head provided with an IC socket, a connection terminal of the IC socket and an external terminal of the IC device to be tested are brought to contact each other by pressing the IC device to load on the IC socket. As a result, the IC device to be tested is electrically connected to a testing main device via the test head and a cable. Then, a test signal supplied from the testing main device to the test head via the cable is applied to the IC device to be tested, and by sending a response signal read from the IC device to be tested to the testing main device via the test head and the cable, electronic characteristic of the IC device to be tested is measured.
A thermal stress of a low temperature and high temperature is applied to the IC device to be tested in the IC device test. As a method of giving a thermal stress to the IC device to be tested, for example, a method of covering the test head provided with the IC socket and controlling the temperature in the chamber, and a method of heating or cooling the IC device to be tested in advance before transferring the same into the test head are used.
Also, in the IC device test, it is necessary to heat or cool the IC socket for loading the IC device to be tested while heating and cooling the IC device to be tested so as to apply a thermal stress. It is because when there is a temperature difference between the IC device to be tested and the IC socket, a heat transfer arises between the two at the time of loading the IC device on the IC socket and the thermal stress given to the IC device may be eased. Also, when a degree of thermal expansion or thermal contraction is different between the IC device and the IC socket, the external terminal of the IC device does not accurately the connection terminal of the IC socket at the time of loading the IC device on the IC socket and contact credibility of the two may be lost. Particularly, when the IC device to be tested is a large sized IC device, such as a strip format IC device, an effect of thermal expansion and thermal contraction is widely different, so that it is necessary to heat or cool the IC socket together with the IC device to be tested to secure the contact credibility of the IC device and the IC socket.
When applying a thermal stress to the IC device to be tested, in the case of using a method of covering the test head provided with the IC socket with a chamber to control the temperature in the chamber, the IC device to be tested and the IC socket are both arranged in the chamber, so that the IC device and the IC sockets are heated and cooled together. However, since a lower side (a test head side) of the socket board on which the IC socket is mounted is exposed to an outside air, there arises a heat transfer between the IC device and the socket board so that the thermal stress applied to the IC device is liable to be eased.
Thus, a method of considering the thermal stress on the IC device being eased to set the temperature in the chamber to be able to make up in advance and a method of circulating the air in the chamber to the lower side of the socket board, etc. are used.
On the other hand, when applying a thermal stress to the IC device to be tested by a method of heating or cooling the IC device in advance of transferring the same to the test head, it is necessary to heat or cool the IC socket by a different method therefrom.
A method of heating or cooling a socket guide by providing a heat source (for example, an electric heater) or a cool source (for example, a Peltier element) to heat or cool the IC socket is used. For example, a method of burying a heating wire in the socket guide and generating heat by applying a current into the,heating wire to heat the IC socket is used.